In a situation where competition becomes intense, health care organizations constantly strive to provide more services with given personnel and time. While not only the 'quantity' of the services but also the 'quality' becomes increasingly important, various problems that can occur during the 'process' of service provision can be effectively managed by applying the methods of management science. In this study, we introduce the cases where the methods of management science can be applied for the management of health care organizations in Korea and abroad. There are many cases where various scenarios for improving the patients' accessibility to the services and for maximizing the efficient use of limited resources are established, and simulation or basic statistical analysis methods are used to solve the problems more systematically or to develop improvement plans. In this study, several exemplary cases, such as no-show of patients, crowding in the emergency room, prediction of the number of available beds in the intensive care units, nurse scheduling, delay of arrival of patients, and ordering of the proper amount of therapeutic materials, are introduced and discussed. From the perspective of administrators or clinicians, however, it may not be easy to master the methodology that requires considerable mathematical background or apply the theories to practice directly. Therefore, it is suggested that more practical and relatively simple analytical methods should be applied. Also, having a more positive attitude toward improving the current performance (e.g., a belief that 'we can always be better than now'), and paying attention to improving the job satisfaction by addressing problems, with experimental spirit and data-driven decision management.